online self-study autoclave. introduction north carolina medical waste rules (15a ncac 13 b.1200),...
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ONLINE SELF-STUDY
Autoclave
Introduction
North Carolina medical waste rules (15A NCAC 13 B .1200), require that "Regulated Medical Waste", defined as "blood and body fluids in individual containers greater than 20 ml, microbiological waste, and pathological waste,” be treated before disposal in order to render the waste nonhazardous.
Autoclaving changes the biological character of the waste to reduce or eliminate its potential for causing disease.
Additional autoclave information can be found at www.ehs.unc.edu under the Biological Safety link.
Proper Disposal of Biohazard Waste
Principles of Autoclave Operation
• Steam penetrates objects in the autoclave
• Condensation creates negative pressure and draws in additional steam
• Moist heat kills microorganisms via coagulation of proteins
• Two types of autoclaves• Gravity Displacement
• Vacuum/Gravity Assisted
Gravity Displacement
In a gravity displacement
autoclave cold air escapes through the bottom of the chamber as steam displaces it from
above. The valves should never be
obstructed and the chamber must not
be overfilled in order for this
system to function efficiently.
Vaccum/Gravity
ClosedClosed
OpenOpen
SteamSteam
SteamSteam
ClosedClosed
OpenOpen
SteamSteam
SteamSteam
OpenOpen
SteamSteam
SteamSteam
A vacuum/gravity autoclave pulls pressure from the chamber.
Types of Autoclaves
Bulk Autoclaves Found throughout UNC-CH
DLAM facilities. Each DLAM facility’s bulk
autoclave may operate differently. Training on the use of each
facilities bulk autoclave is to be conducted and documented by the facility supervisor.
Types of Autoclaves
Tuttnauer Autoclaves Act as both a gravity
displaced and vacuum assisted autoclave. Most autoclaves on campus
perform both. Depends upon the cycle used
to sterilize material. Some of these use “house”
steam from the UNC Steam Plant.
Others use “clean” steam (deionized water).
Uses ‘house’ steam
Uses deionized water/steam
Has an additional
gauge
Types of Autoclaves
Other Manufacturers:
NOTE: Even though autoclaves on UNC campus operate similarly in the context of mechanics, training is required in the use of each autoclave since not all autoclaves are programmed the same.
Steris Castle Getinge
Preventative Maintenance
Plug Screen/Drainer: In order to maintain the autoclave’s effectiveness:
The plug screen or drainer should be removed with heat-resistant gloves, checked, and cleaned frequently to ensure that it is free of dirt, dust, or sediment which may collect and cause a clog. Look out for any sharps that may have become loose and caught in the plug screen/drainer.
Plug screen/drainer location. Plug screen/drainer.
Preventative Maintenance
Surfaces: The interior surfaces should be cleaned (according to
manufacturer’s specifications) of any residues that collects over time.
Debris around drain inside autoclave.
Interior of autoclave.
Preventative Maintenance
Surfaces: On a regular basis, gaskets, doors, shelves and walls
should be visually inspected for residue buildup and wear.
**NOTE If any problems are experienced with the autoclave
contact Facilities Services (962-3456) immediately.
Melted plastic on a shelf from an un-autoclavable container.
Gasket Around Door Gasket Around
Autoclave Jacket
Preventative Maintenance
Air Filters: Some autoclaves have air filters in the
exhaust located directly above to allow for the exhaust of steam when the autoclave is opened. Check the filter from time to time to ensure
that it is not clogged. Contact the appropriate personnel to replace the filter and clean off any debris that has collected.
Pre-Autoclaving Procedures
Before being autoclaved: Contaminated materials should
remain in the laboratory. Biohazard waste containers
should be removed for autoclaving when they are 2/3 full.
Biohazard bags should be closed and placed within secondary containers (bins, trays).
DO NOT USE REDDISH -ORANGE BIOHAZARDOUS BAGS AS THEY WILL MELT
Un-autoclaved bio-hazardous bags left on the floor beside an
autoclave.
Bio-hazardous waste storedin secondary containment
INCORRECT
CORRECT
Pre-Autoclaving Procedures
Indicator Tape (Heat Sensitive Tape): Indicator tape should be applied to the
biohazard bag as it will aid in reducing the handling of the biohazard waste during removal.
The indicator tape should be placed in an “X” pattern over the biohazard symbol.
Indicator tape should change color after autoclaving (i.e. the word ‘Autoclaved’ appears on the tape after treatment.)
Indicator tape is available through Fisher Scientific (www.fishersci.com)
Indicator tape in an “X” pattern.
Not autoclaved (no markings on tape)
Autoclaved (markings on
tape)
What can be autoclaved
Surgical Instruments Glassware Plastic tubes and pipette tips Solutions and water Animal food and bedding Waste
Proper Autoclave Use
Proper temperature and exposure time are critical in ensuring the reliability of the autoclaving process. These factors are dependent upon steam
penetration to every part of the waste load. If all the air is not allowed to escape from the waste
during the autoclave cycle, then steam will not replace the air.
The autoclave user must be mindful to prevent the entrapment of air. (i.e. leaving the biowaste bag open inside the autoclave, removing the lid on sharps containers inside the autoclave.)
PPE for Autoclave Users
Eye Protection
Lab Coat, Buttoned
Closed-toed Shoes
Heat-resistant Gloves
Hazards Associated with Autoclaves
High temperatures and presence of extremely hot water which is not vented creates potential for burns and scalding
Inadequate decontamination allows for the potential of biological hazards and personnel and environmental contamination
Large heavy doors and loading carriages also present an ergonomic and pinch hazard to employees.
Hazards Associated with Autoclaves
How to prevent hazards associated with autoclave use: Read the owners manual as manufacturer
recommendations vary. Make sure autoclave doors and gaskets are firmly
locked into place before operating the autoclave. These interlocking mechanisms help to prevent a
sudden release of high pressure steam. If the autoclave does not have interlocking
mechanisms, take additional precautions to ensure the door is closed.
Hazards Associated with Autoclaves
How to prevent hazards associated with autoclave use:Post a warning sign stating, “Hot Surfaces, Keep
Away” on or next to the autoclave to remind people of the heat hazard as older autoclaves may have little or no heat shielding around its exposed sides.
Never stack or store combustible near an autoclave.
Never autoclave toxic chemicals including residual Trizol, bleach, etc., volatile, or radioactive material.
Contact UNC EHS (962-5507) if you have Biohazardous waste that contain any of these materials.
Hazards Associated with Autoclaves
How to prevent hazards associated with autoclave use : Remove solutions from the autoclave slowly and
gently. Some solutions have the potential to boil over when
moved or exposed to room temperature. Heat-resistant gloves, safety goggles and a
faceshield, and a rubber apron must be worn when removing hot liquids from the autoclave.
Clean up spills immediately. Report malfunctions or accidents to your
supervisor immediately.
Autoclave: Performance Indicators
How to know if autoclave is functioning correctly: Physical - Annual testing every two years by N.C. Dept. of Labor
- Pressure, Temperature, Cycle times, recorded
Chemical -Heat sensitive autoclave tape
- Not an indicator of successful sterilization, useful to keep track of autoclaved and unautoclaved items
Biological - Tests ability of autoclave to sterilize effectively
- Geoacillus stearothermophilus spore strips often used because they are resistant to steam sterilization.
Autoclave Sterilization Procedures- Liquid
Materials The autoclave must have a ‘LIQUID’ setting
that can be used for liquid materials. The settings for liquids run for a longer period at a lower temperature to minimize liquid evaporation and spills.
Liquids should be placed in borosilicate (Kimax or Pyrex) or polypropylene containers for autoclaving and these containers should be filled to no more than 75% capacity.
****Add an additional 20 minutes to the liquid cycle to ensure maximum sterilization****
Autoclave Sterilization Procedures- Liquid
Materials The caps/stoppers on the containers should
be loosened. Never autoclave sealed containers of liquid as
this could result in an explosion of superheated liquid.
Liquid containers should be placed in a stainless steel or polypropylene tray with ¼ to ½ inch of water in the bottom on the tray. This tray should be placed on a shelf in the
autoclave, but not on the bottom of the chamber.
Polyethylene trays should NOT be used as they may melt and cause damage to the autoclave.
Autoclave Sterilization Procedures- Solid
Materials Never overfill biohazard waste bags or the
autoclave. Waste bag should be at least three fingers wide at
the opening of the taped bag. Keep biohazard waste bags slightly opened to
allow for proper steam penetration. Place packaged material in a secondary container
Stainless steel tray or autoclavable polypropylene bin Add between 50-100 ml (¼ – ½ cup) of water to
each bag of solid waste to promote steam penetration. Note: If there is naturally occurring water in the load,
adding additional water is not necessary.
Loading the Autoclave
Load material to allow efficient steam penetration (do not overfill the chamber)
Do not allow material to touch the sides or top of the chamber
Autoclave clean items and waste separately
Operating the Autoclave
Be sure the autoclave is functioning properly before use
Record information in User Log Check strainer and remove any
debris Close door properly and securely Choose the correct conditions for
your material Make sure door to autoclave room
remains closed as this prevents the loss of negative air pressure, therefore preventing the release of odors.
Autoclave Explosion
These pictures represent the results of an improperly closed
autoclave door.
http://www2.umdnj.edu/eohssweb/aiha/accidents/AutoclaveExplosion.htm
Autoclave Waste Decontamination
Procedures Autoclaves are to be
operated at 121°C (250°F) or higher for a minimum of 60 minutes. Some biohazard waste
may be required to be autoclaved for a different set amount of time.
Material Temperature Time
Laundry 121°C (250° F) 30 Minutes
Trash (Biohazard bags containing infectious waste.)
121°C (250° F) 1 Hour
Glassware 121°C (250° F) 1 Hour
Liquids 121°C (250° F) 1 Hour
Animals 121°C (250° F) 8 Hours
Autoclave Waste Decontamination
Procedures
Unloading the Autoclave
Put on Personal Protective Equipment Allow the autoclave to completely finish cycle
Pressure gauge must read zero Verify cycle conditions were met Open door slightly to allow steam to escape While slowly opening the autoclave door,
make sure to keep head, face, and hands away from the opening.
Verify that heat sensitive tape has changed color or word “autoclaved” has appeared.
Allow contents to cool before removal
What’s Wrong With These Pictures?
No secondary container (bin/tray)No autoclave tape
Autoclave Testing & Verification
N.C. Medical Waste Rules require that: Autoclaves be monitored and tested weekly
under conditions of full loading for effectiveness in killing microorganisms.
This is achieved through the use of Biological Indicators such as Geobacillus stearothermophilus (with average spore populations of 104 to 106 organisms).
Use of a Biological Indicator: Tape the indicator to a brightly colored sheet of
paper OR tie it to a long piece of string hanging out of bag so that it can be retrieved after the autoclaving cycle has completed.
Run the autoclave cycle for 60 minutes at the designated decontamination cycle.
Once the cycle has completed and the contents have cooled, don all proper PPE and remove the indicator from the waste bag.
Autoclave Testing & Verification
Incubation of Biological Indicator: The autoclaved indicator and an un-autoclaved
control indicator are then incubated as recommended by the manufacturer.
Check for signs of growth at regular intervals during the incubation period (8, 12, 24, and 48 hours).There should be signs of growth on the controlled
indicator or the test is considered to be invalid. If there is growth on the autoclaved indicator, then
the material was not properly autoclaved.
Autoclave Testing & Verification
Incubation of Biological Indicator: If growth is discovered on the autoclaved indicator:
The autoclave process needs to be re-evaluated: Time, temperature, and autoclaving procedures should be
reviewed. If a mechanical problem is determined to be the culprit,
Facilities Services should be contacted immediately for repair (962-3456).
The waste does not have to be held until the results of the testing confirm effectiveness.
However, the autoclave should not be used until it is repaired. Once repaired, the first load run in the autoclave should be
tested with a biological indicator to ensure that the autoclave is functioning properly.
Autoclave Testing & Verification
Autoclave Testing Results: Autoclave Testing Log
A log of each test should be maintained and kept near the autoclave.
The log should include the following information:
The type of indicator used. Date the test was conducted. Time the test was conducted. Result of the test.
An autoclave testing log can be printed off the UNC EHS website and is available at the following link:
http://ehs.unc.edu/ih/biological/autoclave.shtml
Autoclave Testing & Verification
Autoclave Testing Log
•Maintain a copy of the current form at the autoclave station •Maintain logs for 3 years
Questions?
Call 962-5507
Ask for the Biological Safety Section